Since d(t) is a quadratic function, it is of the form 

. Since we are told that we have 5 solution:







are solutions, we assume they are truthful, pick three
of them, and have the system:





Solving that system gives A=-1, B=9, C=-15, and we take their word
for it that the other two are solutions, and therefore, the quadratic 
equation is:



We know it is concave downward, because the leading coefficient A=-1 is
negative. So we know it has a maximum value

We use the vertex formula:


(4.5,5.25), so the maximum value is 5.25

So (A) is false.

The axis of symmetry is . 

So (B) is false.

The range of the function is from negaive infinity to the maximum value, or
the range is 

So (C) is false.

The function is neither increasing nor decreasing at its maximum
point (4.5,5.25).

So (D) is false.

So they're all false.

Edwin