Fluorine has seven electrons in its outer energy level. according to the octet rule,

it wants to take on another electron
it wants to give up an electron
its outer energy level is full

Option A

Explanation:

Octet rule applies to element and it says that in order to achieve noble gas configuration, the outermost shell (valence shell) must have eight electron.

Given

Number of electrons in fluorine in its outermost shell

Number of electrons to fulfill the octet rule

Deficiency of electron Number of electrons to fulfill the octet rule Number of electrons in fluorine in its outermost shell

Substituting the given values in above equation, we get

Deficiency of electron

Hence, option A is correct.