Which of the Following Is an Example of a Discretionary

Which of the following is an example of a discretionary trust?

A) A transfer of land made in the names of Terry and June to hold the property on trust for themselves as joint tenants .
B) A transfer of land made in the names of Terry and June to hold the property on trust for themselves as tenants in common in equal shares.
C) A transfer of land made in the names of Terry and June to hold the property on trust for Mark.
D) A transfer of land made in the names of Terry and June to hold the property on trust for occupation by such one or more of Mark's children as they shall from time to time determine.