We can analyze the pattern of the sequence. The sequence is as follows:

1, 1, 2, 1, 3, 2, 1, 4, 3, 2, 1, 5, 4, 3, 2...

We can see that the numbers form a pattern. The pattern is as follows:

• 1,
• 1,2, 
• 1,3,2,
• 1,4, 3, 2,
• 1,5, 4, 3, 2 
• Next pattern sequence should be 1, 6, 5, 4, 3, 2, 
• Next pattern sequence should be 1, 7, 6, 5, 4, 3, 2, 

We can determine the sum of the first 28 terms.

Using this information, we can calculate the sum of the first 28 terms as follows:

1 + 3 + 6 + 10 + 15 + 21 + 28 = 84

• Therefore, the sum of the first 28 terms in the sequence is 84, which corresponds to option (b).
• The correct answer is (b) 84.