Suppose V is the set of complex numbers. Which of the following operations can serve as the meet operation for a semilattice on V?  a) Addition: (a + ib) A (c + id) = (a + b) + i(c + d).  b)...

Suppose V is the set of complex numbers. Which of the following operations can serve as the meet operation for a semilattice on V?

a) Addition: (a + ib) A (c + id) = (a + b) + i(c + d).

b) Multiplication: (a + ib) A (c + id) = (ac — bd) + i(ad + be).

c) Componentwise minimum: (a + ib) A (c + id) = min(«, c) + i mm(b, d).


d) Componentwise maximum: (a + ib) A (c + id) — max(a, c) + imax(6, of).