You are given a science question (easy-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.

Which is a fact rather than an opinion about earthquakes?  
 (A) Earthquakes occur along fault lines. (B) Earthquakes are worse than hurricanes. (C) Earthquakes are bad for all local businesses. (D) Earthquakes always cause major damage to homes.
A

When nitrogen-rich runoff from farms enters a nearby farm, it causes abundant growth of algal mat on the pond surface. As a result, underwater plants in the pond begin to die. Identify the limiting factor that is most responsible for causing the underwater plants to die.  
 (A) oxygen (B) sunlight (C) nitrogen (D) carbon dioxide
B

An organism's traits are largely determined by the genetic makeup of its parents. A mutation in which kinds of cells in a parent could cause a new trait to appear in the parent's offspring?  
 (A) sperm or egg (B) egg or nerve (C) nerve or muscle (D) muscle or sperm

A