PLEASE HELP ASAP

Which statement shows how the product of (x + 7)2 demonstrates the closure property of multiplication?
A: x2 + 14x + 49 is a polynomial
B: x2 + 14x + 49 may or may not be a polynomial
C: x2 + 49 is a polynomial
D: x2 + 49 may or may not be a polynomial

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =

The area of square garden is 300m squared. how long is the diagonal?

Which of the following is an equation of a line parallel to the equation y=4x+1?