Interneurons are a broad class of neurons found in the human body that creates circuits between sensory and motor neurons.
So, the option (c) is also incorrect.
Bipolar neurons are having two extensions and are specialized sensory neurons for the transmission of messages.
So, the option (d) is incorrect.
Neurons help to convert a specific type of stimulus into action potential. Motor neuron controls the effectors organs like muscles and glands.
Hence, the correct answer is