Final answer:
Juliet suggests Romeo leave and return later to meet at Friar Laurence's cell where they plan to get married.
Step-by-step explanation:
In lines 148 to 154 of Shakespeare's Romeo and Juliet, Juliet proposes an arrangement with Romeo. The correct answer is option (a): Juliet proposes that Romeo leaves and comes back later; they decide to meet at Friar Laurence's cell to be married. This moment in the play establishes a plan for Romeo and Juliet to overcome their families' opposition and be together, marking a pivotal step towards their ill-fated union.