Choose the correct option which is substitute for/of the underlined word

[Untaught88]

Hi,

Which preposition is correct in the following sentence?
Choose the correct option which is substitute for/of the underlined word.

 

[emsr2d2]

Hi, Unnecessary. Keep posts short and simple.

Which preposition is correct in the following sentence?
Choose the correct option which is substitute for /of the underlined word.