Which of the following is equivalent to cosine56\({}^{\circ}\)cosine23\({}^{\circ}\) - sine23\({}^{\circ}\)sine56\({}^{\circ}\)?

W) sine 33\({}^{\circ}\)

X) cosine 33\({}^{\circ}\)

Y) sine 79\({}^{\circ}\)

Z) cosine 79\({}^{\circ}\)
Z) COSINE 79\({}^{\circ}\)