The fourth sentence after rearrangement is sentence E.

The correct sequence of the sentences is B, 1, A, C, E, 7, D.$

The passage talks about the difference between MARXIST and socialist feminism.$

Sentence B comes 1st as it introduces the topics and completes 1. Then the passage moves on to give some information about Marxist feminists, hence sentence A is 2n$d. $Sentence C is 3rd$ as 'they’ refer to the Marxist feminist thinkers. Sentence E is 4$th as it starts with 'in contrast’, and says why socialist feminists are different from the Marxist ones. This leaves sentence D at the last, completing the 7th sentence.$

1. $Although it is possible to distinguish between Marxist and socialist feminist thought, it is quite difficult to do so.$

2. Classical Marxist feminists work within the conceptual terrain laid out by Marx, Lenin, Engels, and other 19th century thinkers.$

3. They regard classism rather than sexism as the fundamental CAUSE of women's oppression.$

4. In contrast, socialist feminists are not certain that classism is women's worst or only enemy.$

5. They write in view of Russia’s 20th century failure to achieve socialism’s ultimate GOAL - $namely, the replacement of class oppression and antagonism with “an association, in which the FREE development of each is the condition for the free development of all.”

Hence the correct answer is option 5.