The correct option is
A 708,409,067
Tom's number = 23,654,793
Lina's number = 684,754,274
Sum = Addition of Tina's and Lina's numbers
= 23,654,793 + 684,754,274
Let's add the numbers using vertical addition.
Arranging them according to their place values, we get:
Therefore, the sum of the numbers is 708,409,067.