Do all people with autism exhibit the same symptoms

No

All people with autism do not exhibit the same symptoms.

Autism is a complex developmental condition that manifests during the first three years of an individual's life. Autism occurs due to the effect of a neurological disorder on normal brain function, which then influences an individual’s social interaction skills, communication and developmental language. Autism has a range of symptoms which may be mild for some and more severe for others.  Symptoms of autism disorder include repetitive behaviors, seizures, lack of spoken language etc.

a, i am pretty sure.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.