To date, physicists have investigated the behavior of matter and energy at temperatures as high as those that existed in the universe as far back as after the Big Bang.

10-10 second

Explanation:

The physicsist investigated behavior of matter and energy at higher temperature as those that existed in the universe as far back as 10-10 second after the Big bang.

This type of research or investigation is considered as condensed matter physics, which deals with properties of matters in terms of macroscopic and microscopic nature of the matter.

The main purpose of carrying out such investigation is for physicists to determine the behaviour of solid and liquid phases of matter which comes as a result of electromagnetic forces between atoms.

In trying to understand these phases of matter, they make use of physical laws, such as quantum mechanics, electromagnetism and statistical mechanics.

answer; /// i believe that the correct answer is (c)