Explain the meaning of 5?
a. 1 + 2 + 3 + 4 + 5
b. 5-4-3-2-1-0
c. 0 x 1 x 2 x 3 x 4 x 5
d. 5 ∙ 4 ∙ 3 ∙ 2 ∙ 1​