The first and last note of each measure needs to be a chord tone. The chord tones are the notes in the chords shown in the bottom staff.
At least two passing tones and two neighbor tones need to be used correctly.
Only quarter notes, half notes and quarter rests can be used (at least one of each). The last measure may have a whole note.
Listen to the playback to make sure everything sounds right.
Choose one or the other: