Explanation

Somadeva authored the Kathasaritsagara, Ashvaghosha wrote the Buddhacharita, and Bilhana composed the Vikramankadevacharita — all three pairs are correctly matched. The Vasavadatta, however, is a work of Subandhu, not of Kalidasa (whose famous works include the Shakuntala and Meghaduta). Hence the Kalidasa : Vasavadatta pair is not correctly matched.