Suppose now that R(A,B) and S(A,B) are two relations with r and s tuples, respectively (again, not necessarily distinct). If m is the number of (not necessarily distinct) tuples in the result of the SQL query:
R intersect S;
Then which of the following is the most restrictive, correct condition on the value of m?
a) m = min(r,s)
b) 0 <= m <= r + s
c) min(r,s) <= m <= max(r,s)
d) 0 <= m <= min(r,s)

Answer: d
Explanation: The value of m must lie between the min value of r and s and 0.