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.

Many things can contribute to the development of a theory. A student made a list of some things that might help scientists develop a theory. Observations Calculations Conversations Publications From the student's list, which must be used in the development of every theory?  
 (A) Observations (B) Conversations (C) Publications and calculations (D) Calculations and conversations
A

What is the MAJOR reason Earth has seasons?  
 (A) Earth has a moon (B) Earth has a tilted axis (C) Earth has a magnetic field (D) Earth has an elliptical orbit
B

In Type 1 diabetes, the immune system attacks the pancreatic cells that produce insulin. Without insulin, people that have Type 1 diabetes are unable to regulate blood glucose levels. What two symptoms are most likely associated with Type 1 diabetes?  
 (A) extreme thirst and weight loss (B) intense aches and spasms (C) severe loss of hearing and vision (D) excessive loss of coordination and memory

A