function as and which

[kiranlegend]

1. Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.

A) their horny jaws function for teeth
B) its horny jaws function for teeth
C) its horny jaws function as do teeth
D) the horny jaws function as teeth do
E) the horny jaws function as teeth

Here the answer is E. I choose D. Why is E preferred over D?


2. In order for an organism to evolve or survive any length of time, it must learn to somehow deal with the issue of UV rays, which implies that the very oldest sorts of organisms that exist on Earth today all have mechanisms such as the production of sunscreen pigments like melanin, also known as tanning, to protect themselves.

A) which implies that the very oldest sorts of organisms that exist on Earth today all have
mechanisms such as the production of sunscreen pigments like melanin, also known as tanning, to protect themselves.
B) which infers the fact that the very oldest sorts of organisms that exist on Earth today all have mechanisms such as the production of sunscreen pigments like melanin, also known as tanning, to protect themselves.
C) which is inferred from the fact that the very oldest sorts of organisms that exist on Earth today all have mechanisms such as the production of sunscreen pigments like melanin, also known as tanning, to protect themselves.
D) which can be interpreted from the fact that the very oldest sorts of organisms that exist on Earth today all have mechanisms such as the production of sunscreen pigments like melanin, also known as tanning, to protect themselves.
E) which can be implied from the fact that the very oldest sorts of organisms that exist on Earth today all have mechanisms such as the production of sunscreen pigments like melanin, also known as tanning, to protect themselves.

Please explain both the above questions:)

[kiranlegend]

anybody there?:)