The following program generates an error. Why?

const int NUM$\_$ELEMENTS $=5$;

vector userVals$($NUM$\_$ELEMENTS$)$;

unsigned int i;

userVals.at$(0)=1$;

userVals.at$(1)=7$;

userVals.at$(2)=4$;

for $($i $=0$; i $<=$ NUM$\_$ELEMENTS; $++$i$)\{$

cout $<<$ userVals.at$($i$)<<$ endl;

$\}$

Group of answer choices

Variable i is declared as an unsigned integer.

The vector userVals has $5$ elements, but only $3$ have values assigned.

The integer NUM$\_$ELEMENTS is declared as a constant

The for loop tries to access an index that is out of the vector's valid range.