Which statements about opposites are true?

select each correct answer.

a. the opposite of zero is zero.

b. the opposite of a negative number is always a positive number.

c. a number and its opposite are located the same distance from zero on a number line.

d. the product of a number and its opposite is always 1.

ill give brainliest

Sam is a waiter at a local restaurant where he earns wages of $5 per hour sam figures that he also eams about $3 in tips for each person he serves sam works 6 hours on a particular day. if n represents the number of people sam serves that day, which of the following functions could sam use to figure ehis total earings for the do o a. en) = 30 o b. en) = 5n+ 18