[General] Subtle difference between words

As I come through many questions on LSAT and GMAT's RC passages, I frequently find that exact meaning of same adjective words can make huge difference in answers.
Please go through the below excerpt taken from one RC passage:
---
Present planning, thinking, and legislation will not produce the kinds of New Town that have been successful abroad. It will multiply suburbs or encourage developments in areas where land is cheap and construction profitable rather than where New Towns are genuinely needed.
The promoters of New Towns so far in the United States have been developers, builders, and financial institutions. The main interest of these promoters is economic gain. Furthermore, federal regulations designed to promote the New Town idea do not consider social needs as the European New Town plans do. In fact, our regulations specify virtually all the ingredients of the typical suburban community, with a bit of political rhetoric thrown in.
---
Question is:
What is author’s tone in discussing “developers, builders, and financial institutions".
options are:
(A) critical
(B) pedantic
(C) evasive
(D) captious
(E) vitriolic

I surely eliminated B, C and E but spent time to decide on whether A or D because "critical" and "captious" both express "faultfinding". Luckily I made it correct but I want to know the subtle difference between two words and their usage. Thanks a ton.

[Raymott]

Originally Posted by priyankur

As I come through many questions on LSAT and GMAT's RC passages, I frequently find that exact meaning of same adjective words can make huge difference in answers.
Please go through the below excerpt taken from one RC passage:
---
Present planning, thinking, and legislation will not produce the kinds of New Town that have been successful abroad. It will multiply suburbs or encourage developments in areas where land is cheap and construction profitable rather than where New Towns are genuinely needed.
The promoters of New Towns so far in the United States have been developers, builders, and financial institutions. The main interest of these promoters is economic gain. Furthermore, federal regulations designed to promote the New Town idea do not consider social needs as the European New Town plans do. In fact, our regulations specify virtually all the ingredients of the typical suburban community, with a bit of political rhetoric thrown in.
---
Question is:
What is author’s tone in discussing “developers, builders, and financial institutions".
options are:
(A) critical
(B) pedantic
(C) evasive
(D) captious
(E) vitriolic

I surely eliminated B, C and E but spent time to decide on whether A or D because "critical" and "captious" both express "faultfinding". Luckily I made it correct but I want to know the subtle difference between two words and their usage. Thanks a ton.

You'll rarely hear the word captious being used. (I can't remember ever having heard it). Captious means petty fault-finding, being difficult to please. The author doesn't exhibit that. He is making one specific criticism.