The question is referring to two statements about the Constitution of India. The first statement declares that no provision in the Constitution encourages equal pay for equal work for both genders, which is incorrect. Article 39(d) in the Constitution clearly promotes equal pay for equal work for both men and women. Hence, the first statement is wrong.

The second statement asserts that the Constitution of India does not define backward classes, which is correct. The Constitution does not explicitly provide a definition for the term `backward classes`, though it mentions it in several articles such as Articles 15(4), 16(4), and 340. Therefore, the second statement is accurate.

Thus, among the provided options, Option 2 (II only) is correct - meaning only the second statement is true.