Which of the following disabilities is often not immediately apparent to others?

Dyslexia is often not immediately apparent to others because it is a learning disability that primarily affects reading and language processing. Individuals with dyslexia may have normal intelligence and may appear to be functioning typically in social situations. The challenges presented by dyslexia, such as difficulties in word recognition, spelling, and decoding, are often not visible, which can lead to misunderstandings regarding a person's abilities.

In contrast, conditions like blindness and paraplegia typically have visible signs, making them easier for others to recognize. Autism can present with social communication challenges that might not always be evident in initial encounters, but behaviors associated with autism can sometimes be recognized by observant individuals. However, dyslexia is distinct in its invisibility; unless a person discloses their condition or is observed in specific learning environments, it may go unnoticed by others.