Which of the following represent the properties of carbon nanotubes?
1. High electrical conductivity
2. Very high tensile strength
3. High thermal conductivity
4. Low thermal expansion coefficient
Select the correct answer using the options given below:

A. 1, 2 and 3 only

B. 1, 2 and 4 only

C. 1, 3 and 4 only

D. 1, 2, 3 and 4

Answer: Option D