Answer:
A). Vibrant
Step-by-step explanation:
The most accurate and precise replacement for the underlined word would be 'vibrant' as it would best restore the meaning of the sentence. 'Vibrant' means 'bright' and something which is 'full of life'. This meaning would complement the meaning of the sentence as the poster must include 'vibrant' (bright and vigorous) and pretty colors that would invite the viewer's attention and elicit a joyous mood. Thus, option A is the correct answer.