The correct answer is D. quick.
Deft means skillful and quick in using the hands. It is the opposite of clumsy. Sturdy means strong and well-made. Delicate means fragile and easily damaged. Quick means fast.
In the sentence “She handled the machine with deft fingers,” the word “deft” is used to describe the woman’s fingers. The woman’s fingers are described as deft because they are skillful and quick in using the machine. The woman is able to use the machine quickly and efficiently because her fingers are deft.
The other options are not as accurate descriptions of the woman’s fingers. The woman’s fingers are not clumsy, sturdy, or delicate. The woman’s fingers are skillful and quick, which is why they are described as deft.