Assertion: The element carbon forms the basic structural framework of more compounds than any other element.
Reason: The carbon-carbon bond is ionic.
A) Both assertion and reason are correct and reason is the correct explanation for assertion.
B) Both assertion and reason are correct but reason is not the correct explanation for assertion.
C) Assertion is correct but reason is incorrect.
D) Assertion is incorrect but reason is correct.
E) Both assertion and reason are incorrect.

Hint: Carbon forms the basic structural framework of a large number of compounds constituting the complete organic chemistry due to its peculiar properties like high catenation power, tetravalency etc.

Complete answer:
Carbon forms the backbone of complete organic chemistry due to various special properties. These properties enable carbon to make a very large number of compounds. These properties are:
> Catenation: Catenation is defined as the self linking property of an element in which the atoms of the same element bond with each other to form long chains or series of atoms. Carbon shows the highest extent of catenation among all elements due to its small size, less diffused atomic orbitals, high C to C bond energy etc. This self linking property of carbon enables it to form a large variety of organic compounds containing a variable number of carbon atoms in the chains.
> Tetravalency: Carbon has an Atomic Number 6 and an electronic configuration of 2,4 in its K and L shell respectively. Since it has 4 valence electrons, hence, to get a stable electronic configuration, it has to either gain or lose all these 4 valence electrons. However, this is not thermodynamically feasible as a large amount of energy change occurs in doing so. Hence, a carbon atom prefers to share all the 4 valence electrons to achieve a stable electronic configuration.
Also, C-C bond is purely covalent as both the atoms have same electronegativity and hence the difference of the electronegativities is Zero.
So, as per the given question, we see that Assertion is correct but Reason is incorrect.

Therefore, option (C) is correct.

Note: Students must keep in mind that Carbon is not the only element that exhibits catenation. No doubt it has the highest catenation power, but there are other elements like silicon which also show catenation to some extent.