Net charge = -1. Option D is correct
Protons are positively charged ion while electrons are negatively charged electron.
Given the following parameters
[tex]\begin{gathered} Proton\text{ number}=49protons \\ Electron\text{ number}=50electrons \end{gathered}[/tex]Determine the net charge
[tex]\begin{gathered} Net\text{ charge}=-50+49 \\ Net\text{ charge}=-1 \end{gathered}[/tex]Hence the net charge of this ion is -1