The first option we have is the polynomial funtion:

To calculate the roots of this polynomial, we need to equal each parenthesis to zero, and solve for x:

And for the second parenthesis equal to zero we have:

This polynomial function has roots 2i and 3i, whith a multiplicity if 1 because they only appear 1 time as a root each.
Also, we need to find if the leading coefficient is 1, for this we need to multiply the two parentesis of the function:

The leading coefficient is the one with the x that has the highest power. Since the highest power is x^2 we can see that indeed it has a leading coefficient of 1.
Thus, the answer is the first option: f(x)= (x-2i)(x-3i)