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.

Scientists wonder how the Egyptian pyramids were built. They think that the huge blocks of stone may have been put into place by pushing them up a sloping pathway. The pathway is which type of simple machine?  
 (A) lever (B) pulley (C) inclined plane (D) wheel and axle
C

Similar types of cells form tissues. What is the next level of complexity formed from the grouping of tissues?  
 (A) organs (B) organelles (C) organisms (D) organ systems
A

Why is it important to repeat an experiment several times?  
 (A) to use up all the materials (B) to give all the students the chance to participate (C) to collect more data to fit the hypothesis (D) to determine if the results are similar

D