Q.

  primary amines react with HONO to form alcohol. Thus, ${\mathrm{C}}_5{\mathrm{H}}_{13} \mathrm{N}$ will be a primary amine. Also, it is optically active. Thus, the only isomer of ${\mathrm{C}}_5{\mathrm{H}}_{13} \mathrm{N}$ which is a primary amine as well as optically active is 2- Aminopentane. 

Following is the reaction that takes place when the compound is reacted with HONO.

Hence, the correct answer is option B) 2-Aminopentane.