A.
B.
C.
D.
参考答案:
C
本题详细解析:
Arrow C is pointing to a round cell with a large nucleus, that is closer to the middle of the tubule than the basement membrane. Choice C is correct.
Choice A is incorrect as it is pointing to the space between the cells (interstitial cells). Choice B is incorrect as it is pointing to spermatids, as indicated by the presence of tails and smaller nuclei. Choice D is incorrect as it is pointing to the basement membrane, the membrane surrounding the seminiferous tubules.