Purple sulfur bacteria and filamentous sulfur-oxidizers both a. accumulate sulfur as intracellular granules. b. fix nitrogen. c. produce oxygen from carbon dioxide. d. use gliding motility.

Option A, accumulate sulfur as intracellular granules.

Explanation:

Purple sulfur bacteria  belong to the group of Proteobacteria. These probacterias are  anaerobic  in nature and yet are able to photosynthesise. They are usually found in  water environments  such as hot springs, stagnant water etc. They use sulphur (either in the form of sulfide, or thiosulfate) as an electron donor in their photosynthetic activity to oxidise sulfur thereby producing granules of elemental sulfur.

while filamentous sulfur oxidizers use nitrate instead of oxygen to oxidize sulfide thereby producing granules.

Hence, option A is correct.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.