What is the title of episode with 5 stars and nominated for Prism Award which is aired on April 19, 2009?
5 stars refers to stars = 5; nominated refers to result = 'Nominee'; Prism Award refers to award_category = 'Prism Award'; on April 19 2009 refers to air_date = '2009-04-19'
SELECT T3.title FROM Award AS T1 INNER JOIN Vote AS T2 ON T1.episode_id = T2.episode_id INNER JOIN Episode AS T3 ON T1.episode_id = T3.episode_id WHERE T3.air_date = '2009-04-19' AND T1.award_category = 'Prism Award' AND T2.stars = 5 AND T1.result = 'Nominee';