To find the ninth term of the arithmetic sequence given by the formula \( a_n = 3.7 + 12n \), we substitute \( n = 9 \) into the formula:
\[ a_9 = 3.7 + 12 \times 9 \]
Calculating \( 12 \times 9 \):
\[ 12 \times 9 = 108 \]
Now, substitute back into the formula:
\[ a_9 = 3.7 + 108 = 111.7 \]
Now we round \( 111.7 \) to the nearest tenth, which remains \( 111.7 \).
Since none of the options provided match \( 111.7 \), let’s double-check if \( a_n \) should have \( n \) starting from 0 or 1. Assuming \( n \) starts from 0 (which is common in sequences), the correct term to look for as the ninth term would be \( n = 8 \):
\[ a_8 = 3.7 + 12 \times 8 \] Calculating that gives:
\[ 12 \times 8 = 96 \] \[ a_8 = 3.7 + 96 = 99.7 \]
Firstly, with \( n = 9 \) (ninth term from the start with n=0) we calculated 111.7. If you meant after a 1-based index (where the first term is a_1) then the ninth would revert to n=8 leading to 99.7, stating that if n truly directed towards starting point at 1 then calculating reduced to a_9=108 (but given based on index not stated necessary thus initially summed terminologies).
Therefore, none of the presented answers are correct if \( n \) indeed stands for a traditional arithmetic sequence starting at zero up to your final summation of last index prior of eight leading to counts derived.
In summary, it looks like there is some miscommunication or a discrepancy in the answer choices.
Under the assumption \( n=9 \) directly targeting includes linear propagation relying upon presented components (meaning closest could annotate towards larger archways) thus final resolution:
None of the choices provided were correct based on direct calculations outlining on their potential derived conclusions.