The first step of the scientific process is A. Making an observation
B. Testing a hypothesis
C. Communicating your findings in a journal

A. Making an observation

Explanation:

Before you can communicate findings, you first need to have findings. And before you can test a hypothesis, you first need to come up with a hypothesis, which can be done by first making an observation.

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.