Intramembranous ossification:

a) occurs inside a bag of cartilage.
b) produces flat bones as in the bones of the roof of the skull.
c) occurs in all bones before birth.
d) occurs in the diaphysis of a long bone.
e) explains how a juvenile's bone can grow in length.

B) produces flat bones as in the bones of the roof of the skull.

Explanation:

intramembranous ossification helps in the formation of  bone from mesenchyme  connective tissue which brings about membrane bones ( bones that form the roof of the skull).it  is a result of initial formation of the flat bones of our skull,  forming our jaw and clavicles, or collar bones and helps with bone fractures gradual healing. it processes initially begins by the formation of centre for ossification, calcification and end product is the formation of bones and periosteum (outside lining of all bones)is  finally formed as the end product.

It is simply the production or formation of the flat bones of the skull, mandible, clavicles e.t.c