Which relation is a function?
me
a.
{(7, 12), (1, –5), (3, –10), (2, –5)}

b.
{(1, 2), (1, 5), (1, –1), (1, 4)}

c.
{(–3, 4), (–2, 5), (0, 9), (0, 12)}

d.
{(8, –1), (2, –1), (3, 8), (2, 5}

Idont understand math at all! : o( use this scenario to answer the remaining questions: brenton purchased a new bedroom set for $4,500.00. he lives in arizona and pays a 8.75% sales tax. if he made a 50% down payment and financed the rest, what amount did he finance? what is the total sales tax brenton will pay? enter your answer in currency format, round to the nearest cent. what was brenton's total amount financed? enter your answer in currency format, round to the nearest cent.

Pls brainliest will be awarded if answer is correct

Madeline takes her family on a boat ride. going through york canal, she drives 6 miles in 10 minutes. later on as she crosses stover lake, she drives 30 minutes at the same average speed. which statement about the distances is true?