Final answer:
The current depth of the diver after swimming upward is -143 feet, which means the diver is still below the surface and is represented by a negative value.
Step-by-step explanation:
The student asks about the current depth of a diver represented by a signed number after the diver swims upward. If the diver starts out at 268 feet below the surface, this is represented by a negative number because it is below the surface level. Swimming upward would mean moving towards the surface, which is the positive direction in this context. So, when the diver swims upward 125 feet, we perform a subtraction: -268 feet (starting depth) + 125 feet (upward swim) = -143 feet. Therefore, the diver's current depth is -143 feet, which is option A.