When plasma Ca concentration decreases... 1. Parathyroid hormone level increases 2. Parathyroid hormone level decreases 3. Ca and phosphate reabsorption increases 4. Ca and phosphate reabsorption decreases 5. Ca reabsorption decreases and phosphate reabsorption increases 6. Ca reabsorption increases and phosphate reabsorption decreases

2. Parathyroid hormone level decreases

4. Ca and phosphate reabsorption decreases

Explanation:

When plasma Ca concentration decreases, the action of Parathyroid hormone level decreases  which leads to Calcium and phosphate reabsorption decreases. Parathyroid hormone is responsible for the increase of calcium and phosphorus in the blood when there is low level in the blood so when the re is huge amount of calcium and phosphorus in the blood, the Parathyroid hormone activity decreases which decrease the reabsorption of calcium and phosphorus decreases.

the correct answer is option d.

an appositive is a noun, noun phrase or noun clause which follows another noun or noun phrase in order to describe it or name it another way. they are usually used between commas, brackets or dashes.

the example sentence with the correct use of commas is the following:

her uncle, the man over there in the red shirt, owns the hardware store in town.