Two point charges q_1 = 2.10 nc and q_2 = -6.20 nc are 0.100 m apart. point a is midway between them; point b is 0.080 m from q_1 and 0.060 m from q_2 (the figure (figure 1) ). take the electric potential to be zero at infinity.

 1)- Va= V(q1 on A)+V(q2 on A)= q1*9*10^9/(d1) +q2*9*10^9/(d2)if these particles in the air = 2.4*10^-9 * 9*10^9 /0.05 + -6.5*10^-9 * 9*10^9 / 0.05 = -738 volt. _ where : d1= the distance between q1 and A. d2 = the distance between q2 and A. 
2)- Vb= V(q1 on B)+V(q2 on A)= q1*9*10^9/(d3)+ q2*9*10^9/(d4) = 2.4*10^-9 * 9*10^9/0.08 + -6.5*10^-9 * 9*10^9/0.06 = -705volt 3)- work = qc*(Va-Vb)= 2.8*10^-9 *(-738-(-705))= -92.4*10^-9 J

My answer is opptionc, just check with anyone else

Texture and composition are different because they are not the same aspect. texture has to do with feel and so on, where as composition is the chemical makeup which you cant touch like you can texture.