Step-by-step Solution:

To determine the number of minterms in the given Boolean expression ( A + BC ), consider the number of variables involved.\[\] 1. The variables involved are ( A, B, C ). There are three variables in total. The total number of minterms possible for three variables is given by ( 2^3 = 8 ).\[\] 2. Each minterm represents a unique combination of the variables ( A, B, ) and ( C ).\[\] 3. The expression ( A + BC ) includes terms corresponding to all combinations of ( A ) being true (( A = 1 )) or ( BC = 1 ).\[\] 4. The expression ( A + BC ) has the following minterms:\[\] \[\] ( A = 1 ): Covers all combinations of ( B ) and ( C ) when ( A = 1 ). There are ( 4 ) combinations (( B ) and ( C ) can each take values 0 or 1).\[\] - ( BC = 1 ): This corresponds to ( B = 1, C = 1 ) and does not overlap entirely with all of ( A ).\[\] Thus the unique minterms covered by ( A + BC ) are those corresponding to these combinations, yielding 5 distinct unique combinations. The number of minterms covered by this expression is thus 5. \[\] Correct Option: (d)