White matter is found in all of the following locations except the a) cerebral cortex b) corpus callosum c) corticospinal tracts d) outer portion of the spinal cord.

cerebral cortex

Explanation:

The tissue through which the messages are relayed between different areas of the grey matter is termed the white matter. The nerve fibers present in the white matter are surrounded by myelin due to which they appear white and hence, the name.White matter is present in deeper parts of the brain and on the superficial parts of the spinal cord in the central nervous system. White matter under normal conditions is absent from the cerebral cortex.

Iam not sure but to me it with be a or dsorry if i was late! hope this ! : )if you really want me to find out the answer that is correct tell me and i will do more research but the a or d makes sense to me.