The correct option is B splendid
'Magnificent' means extremely beautiful or superb. The meaning of the word is option B 'Splendid' which also means grand and impressive. Option A 'popular' means well received or accepted. Option C 'decorative' means beautifying. Option D 'illuminated' means to light up. A, C and D are incorrect meaning to the word 'magnificent'. Thus, the correct option is option B, splendid.