Astudent is conducting their science experiment on the effect of caffeine on dogs. he has 3 groups of test subjects. the 1st group of dogs receives plain water. the 2nd group of dogs receives 10 mg of caffeine each, and the 3rd group receives 50 mg of caffeine each. he will measure their activity levels by recording how long each dog runs without stopping, after giving them the pills. what is the control group

The 1st group of dogs

Explanation:

The control group in an experiment is the group that does not receive treatment, or the one that is not subjected to the independent variable. A control group is used to determine that no other influence or other outside variables would cause the change in the subjects.

For example, if the dogs in the control group would experience the same changes that the dogs that were tested (the ones that got caffeine), then that would mean that it was not the caffeine that elicited the change in the subject.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

i think the answer is b.