Apollen grain contains the male gametophyte, sperm, which is
a. a spermatangium
b. a microsporocyte
c. haploid
d. a gymnosperm

option C, haploid

Explanation:

A male gametophyte develops into the pollen of the flower and consists of two haploid nuclei

a)The germ nucleus

b)The tube nucleus

Both these haploid nuclei’s are contained within the exine of the pollen grain. A male haploid cell contains 50 percent of the exact number of chromosomes as compared to its original chromosome number. In females, the gametophyte  has eight haploid cells.  

clinically, some people often have repeated allergies, eczema and respiratory infections or other parts of the infection, in this case, in addition to some routine tests such as tests for white blood cells, immunoglobulin series, lymphocyte subsets, etc., the five immune immunoglobulin tests are also necessary.