Which one of the following flexibility-based exercises focuses on spinal and pelvic alignment, coordinated breathing, and development of strong core muscles?
a. yoga
b. tai chi
c. pilates
d. pnf

The correct answer is option C. Pilates.

Explanation:

Pilates is a type or method of exercise include more than 500 exercise that provides muscle strength, endurance movements, and flexibility. Pilates focuses mostly on the spine for proper posture and alignment, muscle balance and core strength.

Pilates is developed from exercise from yoga and ballet that benefits the body of individual with flexibility, increases lung capacity for coordinated breathing. Pilates also helps in pelvic alignment and several other ways by the repetition of intense position for five to ten times depending on person to person.

Thus, the correct answer is option c. Pilates.