The is the lowest pitched orchestral stringed instrument.
cello
violin
harpsichord
double bass

Of these four, the correct answer between them would be the double bass.

Violin is the smallest stringed instrument among the stringed instruments and also the highest pitched of them all. Following the options presented on the list, the next one to the violin would be the cello. It's a member of the violin family that is why how it looks is similar to it, though the way they played varies to each other. The harpsichord, on the other hand, is a harp played by how a piano is played. This is not usually used for orchestras. The double bass, lastly, is the largest stringed instrument among the stringed instruments. It is also registered as the lowest pitched orchestral stringed instrument.

The formula is (nh4)2co3