What is a large work for orchestra, usually in four movements, called?

The correct choice is a symphony, which is a substantial musical composition typically written for a full orchestra. It generally consists of four movements, each with its own character and structure, often following the format of fast-slow-dance-like-fast. This structure allows for a range of emotions and musical ideas to be expressed throughout the work.

Symphonies can feature a variety of musical styles and techniques, and they have been a prominent genre in Western classical music since the 18th century. Notable composers like Haydn, Mozart, and Beethoven made significant contributions to the symphonic form, making it a cornerstone of orchestral repertoire.

In contrast, a concerto primarily features a solo instrument with orchestral accompaniment, a sonata is typically a work for one or two instruments, often structured in three movements, and an overture serves as an introductory piece, often preceding an opera or ballet. These other forms, while significant in their own right, do not fit the specific definition required for the question.