If Li loses an electron to another atom why is it written with +1

If an atom loses an electron, it loses one negative charge (since electrons are negative). This means that the atom that was previously neutral becomes a cation (a positively charged atom). If Li was neutral (where it had an equal amount of protons and electrons) before losing an electron, it losing an electron would result in a positive charge being formed as there would then be one more proton than the amount of electrons.

the answer is b & c i believe : )