To find the fewest number of tables needed to seat all the guests attending the party, we first need to determine how many guests will actually attend.
- Start with the total number of invited guests: 163.
- Subtract the number of guests who will not attend: 9.
\[ \text{Number of attendees} = 163 - 9 = 154 \]
Next, each table can seat 12 guests. To find the number of tables needed, we divide the number of attendees by the number of seats per table:
\[ \text{Number of tables} = \frac{154}{12} \]
Now, calculate this division:
\[ 154 \div 12 = 12.8333 \]
Since you cannot have a fraction of a table, we round up to the nearest whole number. Therefore, the number of tables required is 13.
Thus, the fewest number of tables needed to sit all of the guests attending the party is B 13.