The correct form of interesar for the translation of "English class interests me" is the singular, interesa. Why is this true? Explain your answer in 2 to 4 English sentences.

these are the words to choose from to people answer the question:

nieta--yerno--tia--tio--primo--nuera--abuelo--cunada

1.) la ruta arqueologica

2.) la ruta artesanal

3.) la ruta paraiso artesanal  

4.) la ruta de las flores

5.) la ruta sol y playa

6.) la ruta de la paz