Determine the correctness or otherwise of the following Assertion [$a$] and the Reason [$r$].

Assertion [$a$]: A zygote and its immediate descendant cells are unspecialized and are called totipotent

Reason [$r$]: Totipotent cells retain the capacity to differentiate into only a few cell types

1. Both [$a$] and [$r$] are false
2. Both [$a$] and [$r$] are true but [$r$] is not the correct reason for [$a$]
3. Both [$a$] and [$r$] are true and [$r$] is the correct reason for [$a$]
4. [$a$] is true but [$r$] is false