(c) had a mental disease or defect which rendered the victim temporarily or permanently incapable of understanding the distinctively sexual nature of the conduct, including, but not limited to, being incapable of providing consent, or incapable of understanding or exercising the right to refuse to engage in the conduct.
Aggravated sexual assault is a crime of the first degree.
Except as otherwise provided in subsection d. of this section, a person convicted under paragraph (1) of this subsection shall be sentenced to a specific term of years which shall be fixed by the court and shall be between 25 years and life imprisonment of which the person shall serve 25 years before being eligible for parole, unless a longer term of parole ineligibility is otherwise provided pursuant to this Title.