In tennis, a score of forty all in a game is called which of the following?

The correct answer is C, deuce. Points in a game are called fifteen, thirty and forty, and when both players reach forty the score is deuce. From there a player must win two points in a row to take the game, and the game can return to deuce any number of times.

Option A, love, means a score of zero, so a game opening with a point to the server is fifteen love and a set won without dropping a game is six love. Option B, advantage, is the score after a player wins the point immediately following deuce; winning the next point as well gives that player the game, while losing it takes the score back to deuce. Option D, a let, is not a score at all but an order to replay the point, most often called when a serve clips the top of the net and still lands in the correct service box. Knowing all four terms together makes this family of questions straightforward.