11. A. My girlfriend advised paying half for the meal.
"I will pay half" suggests an offer, but the context implies a suggestion or agreement. "Advised" fits best.
12. D. They encouraged my mother to join the yoga club.
"You should join" is a suggestion, and "encouraged" conveys a positive and supportive suggestion.
13. A. She told me to turn off the TV when I wasn't using it.
The original sentence is a direct instruction. "Told" is the most straightforward reporting verb. The tense of "wasn't using" correctly reflects the past time when the TV was not being used.
14. B. She suggested that we go for a walk in the park after school today.
"Let's go" is a suggestion, and the reported speech needs "that + subject + verb."
15. A. My parents advised me to visit my grandparents every weekend. * "You should visit" is a recommendation, best reported by "advised."