+ Q a . b C 1 pt Two point charges of equal size but with opposite signs are held at a fixed distance from each other as shown in the figure. Point "a" is exactly halfway between the point charges. Point "b" and point "c" are under the point charges respectively. Select True or False for the following statements. The electric potential at point "a" is negative. 4. AO True BO False The electric potential at point "c" is negative. 5. AO True BO False The magnitude of the electric field at point "a" is zero. 6. AO True BO False