In order to estimate the total cost, let's consider the most expensive item on the dinner and let's include drinks.
So, listing all costs, we have:
Ben's dinner: $13.80
Friend's dinner: $13.80
Drinks for both: 2 * $1.95 = $3.90
Now, let's calculate the total before the tip and after the tip:

Now, including the movie tickets, we have:

Therefore the total cost is $37.8 + $12 = $49.8.
So a reasonable estimate he will need is $51.00, therefore the correct option is A.