Answer: Intrauterine
Step-by-step explanation:
Intrauterine is the space of the body which is inside the uterus of the pregnant woman.It can contain fetal pole or yolk sac in the gestational sac of the uterus.
According to the question,music is influencing intrauterine environment as Mary is placing headphones on her belly as she is pregnant.She is performing this act to make the baby who is present in gestational sac can listen to the soothing sound for less movement .