Testosterone functions inside a cell by a) coordinating a phosphorylation cascade that increases spermatogenesis b) binding with a receptor protein that enters the nucleus and activates specific genes c) acting as a signal receptor that activates tyrosine kinases d) acting as a steroid signal receptor that activates ion channel proteins

The correct answer is c acting as a signal receptor that activates  Tyrosine kinase

Explanation:

Testosterone is a steroid hormone that is synthesized from cholesterol . Testosterone is secreted from the leydic cells of testis.After being secreted Testosterone is converted to dihydrotestosterone(DHT) .DHT then binds to specific androgen receptor and resulting in the activation of of the receptor.The hormone receptor complex then enter  within the nucleus of the to cell and binds to the specific region of the target DNA,this specific sequence is known as androgen responsive element .This ultimately leads to activation of various protein kinases that ultimately regulates the anabolic function of testosterone.