For intramembranous ossification to take place, which of the following is necessary?
a) an ossification center forms in the fibrous connective tissue.
b) a medullary cavity forms.
c) a bone collar forms around the cartilage model.
d) the cartilage matrix begins to deteriorate.

An ossification center forms in the fibrous connective tissue.

Explanation:

Intramembranous ossification is an important process of formation of bone from the fibrous membrane. This process occur during the the fetal development.

Mesenchyme stem cell in the meduallry cavity starts the process of intramembranous ossification. The important process during intramembranous ossification is the formation of ossification center in the fibrous connective tissue.

Thus, the correct answer is option (A).

answer; ///i believe the correct answer is (

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.