'But' (sentence 1), 'However' (sentence 2), 'The' (sentence 4) and 'We caution that the theory ....' (sentence 5) indicate that none of these opens the topic. Each follows some other sentence(s). As sentence 3 opens the topic (it is clear) options (c) and (e) are eliminated.Sentence 1, states the name of the 'advanced formulation of the theory; hence it follows sentance (3). This eliminates option (b). (1) mentions the 'number of dimensions' as ten and (4) explains what makes this 'ten'. Therefore, (4) follows(i). Sentence (5) gives a 'caution' and (2) states that 'however' or despite the caution the theory has swept research. So, (2) follows (5). Thus, the sequence is 3-1-4-5-2.