A Granddaughter Is Becoming Frustrated Because Her 91-Year-Old Grandfather Never

A granddaughter is becoming frustrated because her 91-year-old grandfather never hears what she says.What advice would you give to this woman to increase the chances that her grandfather will be able to understand what she says?

A) Raise the pitch of your voice so that it will be higher.
B) Keep yelling louder and louder until he finally can hear you.
C) Motivate him with candy.
D) Talk in a low-pitch but distinct voice,and articulate every syllable.