Centrosome was discovered by
A. Boveri
B. Porter
C. Thompson
D. Schimper

Hint: He proposed the chromosomal theory of genetics, he also proposed the cellular process and mechanism of how cancer is caused. The centromere is the main microtubule of the cell organization which plays a major role in cell cycle and cell division. With help of centromere, chromatids are held in a place with mechanical support of spindle fibre in addition.

Complete answer:
He worked on sea urchins.
He proposed and shows that all chromosomes with centromere should be in the correct order for the proper embryonic division to take place.
He discovered the importance of centromere for the formation of spindle fibre during stating the chromosomal theory which takes place in a cell.
This gives the importance to the cell cycle that for completion and cell division centromere plays an important role without centromere cell division will not occur properly and the cell cycle will not get complete.
He marked that while nucleus division of cell two chromosomes can be seen in between the two nuclei as a connective rod between them.
With this, he gives the theory that genetic variation is development caused by the chromosomes.
The PCM contains proteins responsible for microtubule nucleation and anchoring including $\gamma $-tubulin, pericentrin and ninein. In general, each centriole of the centrosome is based on a nine triplet microtubule assembled in a cartwheel structure and contains centrin, cenexin, and tektin.

The correct answer is option ( A) that is Boveri.

Note: Boveri's work was focused on chromosomes which were usually studied in sea urchins and his cancer theory was given by studying sea urchins eggs. Boveri has a major contribution to genetics, cell biology and was known for chromosomal theory and embryonic development. Sea urchins are echinoderms and are found easily all over the water bodies (sea) of the world.