What is the most likely diagnosis for a 13-year-old boy who is highly verbal and intelligent but exhibits inattention, poor grades, difficulty following instructions, and avoids reading/writing?

A) Attention-Deficit/Hyperactivity Disorder (ADHD)
B) Specific Learning Disorder (SLD)
C) Oppositional Defiant Disorder (ODD)
D) Autism Spectrum Disorder (ASD)