Answer:
(a) In her speech from act one, scene v, lines 96 - 99, Juliet is playing with the double meaning of the word "name." She says "O, be some other name! What's in a name? That which we call a rose by any other name would smell as sweet." She is suggesting that the name of the person she loves, Romeo, does not matter, as his true identity is found in his actions and not in his name. She is also using the metaphor of a rose to suggest that love does not change based on a name.
(b) Juliet expresses her frustration towards Romeo's last name as she is from rival family. She says that, the name does not matter, what matters is the love between them. She makes a metaphor of rose, saying that even if it is called by different name, it would smell as sweet. She emphasizes that name is not important but the essence of love is.