Which statement describes an example of irresponsible parenting? A parent sets a regular nightly bedtime for a child. A parent upsets his child by limiting time spent watching television. A parent embarrasses her child by kissing him at school drop-off. A parent leaves his young child home alone while he runs errands.

Bmust be the answer, as technically all organs move, so a is incorrect. all organs are made of different types of cells, so that isn’t a problem, so c is also incorrect. human hearts are very similar to many other animals’ hearts, so d is also incorrect, yet the heart is made of muscle, which is hard to grow in the lab so it would be correct to say b