Final answer:
A melody that moves smoothly and in a stepwise motion is called Legato, which is option B. Legato indicates that the notes are played in a continuous, fluid manner without breaks.
Step-by-step explanation:
The melody that moves smoothly, in a stepwise motion is called Legato. This term comes from the Italian word for "tied together" and signifies that the notes are played in a smooth, flowing manner, with no noticeable breaks between them. The opposite of Legato is Staccato, which means the notes are played in a short, detached manner. Pizzicato refers to plucking the strings of a stringed instrument, and an Arpeggio is when the notes of a chord are played one after another, rather than simultaneously. Therefore, the correct option would be B) Legato.