The most critical defining characteristic of a true experiment is often seen to be a high degree of control over the
a. arrangement of experimental conditions.
b. choice of dependent variables.
c. random assignment of participants to experimental conditions.
d. systematic manipulation of independent variables.

Option (c) is correct.

From the given options, the most decisive peculiarity of a true experiment is given as follow: "generally seen to be a high rate of control over a random assignment of individuals to experimental circumstances.

Thus the correct option in this particular case is (C).

could you go a bit more in depth with you question? it's quite hard to understand. as soon as you do that i will be glad to : )

answer; 35 year old african american man who is also a college graduate;