Extensive tests have been ___ on the patient.

The correct option is:

a) carried out

Explanation: "Carried out" is the appropriate choice in this context because it means that extensive tests were performed on the patient. It is a common phrasal verb for conducting tests, experiments, or examinations.

The other options are not correct for this context and here's why:

b) "Come up" typically means to arise or occur, but it doesn't convey the idea of conducting tests.

c) "Made up" means to invent or create something, not to conduct tests.

d) "Gone through" means to have experienced or endured something, but it doesn't specifically refer to conducting tests.