You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Growth and activities of organisms can speed up the chemical weathering of rocks. Which organisms naturally cause most of the chemical weathering of rocks?  
 (A) small mammals (B) plant seedlings (C) mosses (D) insects
C

In pea plants, the allele for smooth peas is dominant (S). If a heterozygous smooth pea plant (Ss) is crossed with a homozygous smooth pea plant (SS), which are the possible genotypes the offspring could have?  
 (A) only SS (B) only Ss (C) Ss or SS (D) ss or SS
C

Some health care professionals recommend that children use insect repellent before going outside. Using insect repellent is a good way to keep the insects from  
 (A) reproducing. (B) laying eggs. (C) spreading disease. (D) dying.

C