a. All elements in the initializer list must be of the same type.
b. All elements in the initializer list must be implicitly convertible to a known type which is the actual type of at least one member in the initializer list.
c. All elements in the initializer list must be implicitly convertible to common type which is a base type of the items actually in the list
d. There are no restrictions on the items in the initializer list as the array is not declared to be a specific type .