PLLZZ I NEED HELP DUE SOON What type of molecule forms the antibodies found in the human immune system?

Look at the following answer choices and determine which belongs in the both category. testable, can be disproven explains natural phenomena, has evidence to support it prediction, tentative, one or more scientists working together well established, many different scientists working independently, highly reliable

Creation of an unnaturally uniform sample to represent a diverse populationcan be avoided by: a. including only willing b. asking another scientist for .c. choosing only identical participants.d. selecting individuals at random.

The idea of spontaneous generation was disproved by in a experiment involving jars of meat