12.
Your Answer is
Correct Answer is G
Explanation
Look at the sentence components first, the subjects are N1 and N2, the first noun is lizards, lazing in the sun post-attributive modifies the front noun, the second noun is quail, rustling through grasses post-attributive modifies the front Noun, the predicate verb in this sentence is surprised. Therefore, the underlined part should be in the form of doing, and G is correct.