P.D. does not depend upon the path alongwith the test charge q moves
`therefore" "E=(-dv)/(dr)=-((V_(C)-V_(A))/(d))-(V_(A)-V_(C))/(d)`
`d_(AC)=4" So, "V_(A)-V_(C)-Exx4-4^^(E )`
At point C, electric potential will be more since as potential decreases in the direction of electric field
`therefore" "V_(A)-E_(0)=E_(0)xxd.`