To determine the term of the series: we first observe the pattern in the series:
1. The first group has 1 term: .
2. The second group has 3 terms: .
3. The third group has 5 terms: .
4. The fourth group would have 7 terms, and so on. Thus, the number of terms in the group is . Next, we determine the starting number of the group. The series consists of consecutive odd numbers. The total number of terms up to the group is: This is because the sum of the first odd numbers is . Therefore, the starting number of the group is the next odd number after the last term of the group. The last term of the group is: Thus, the starting number of the group is: The group consists of consecutive odd numbers starting from . The sum of these consecutive odd numbers is: However, a simpler approach is to recognize that the sum of consecutive odd numbers starting from is: Substituting : Simplifying the expression inside the brackets: Thus, the sum of the group is: However, upon closer inspection, we realize that the sum of the group can be expressed more simply as: This matches option (4). Therefore, the term of the series is: