The unit of specific conductance is:
A) Ohm
B) Ohm-metre
C) Siemen
D) Siemen per metre

Hint: Specific conductance also known as conductivity is reciprocal of the resistivity. Therefore the unit of conductivity is reciprocal of the unit of resistivity which is per ohm-metre or siemen.
Complete answer:
The unit of specific conductance is siemen. Conductivity or specific conductance is defined as the property of a material to conduct electricity from them. It is reciprocal of the resistivity which opposes the flow of current. The unit of resistivity is ohm-metre. So the unit of conductivity is per ohm-metre or Siemens. Every material has its fixed conductivity and resistivity.
This property is independent of the shape and size of material. The factors which affect these properties are nature of material and temperature. But resistance and conductance are dependent on the length and area of the cross section of material. Conductance and conductivity has a little difference that conductivity does not change by changing its length or area of cross section But conductance changes. Same is with resistivity and resistance. The material having approximately zero resistance is called a super conductor.

Note: Usually unit of resistance is mostly used than unit of conductance. So the unit of conductance can also be expressed in terms of ohm. And also conductivity can be expressed in terms of ohms. But the actual unit of conductance is siemen.