The best reason for viewing mistakes as opportunities is to

avoid guilty feelings.
have an excuse.
prevent future errors.
maintain a positive attitude.

The answer would be the last choice which is to maintain a positive attitude. Maintaining a positive attitude enables the person to view things positively where as when he or she experience mistakes, they will likely view them as a way where it wouldn't affect them negatively. That is why the right answer to the question above is the last option.

Difference between normal and abnormal tissue is much clearer on mri than on ct and mri much suitable to view soft tissues

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