Sponges attach to the ocean floor, continually filtering seawater for food and ejecting water they have just filtered to avoid reingesting it.
Statements
Sponges attached to the bottom of the ocean let seawater in, filter it, and then eject the water they've just filtered away from where their water intake is.
causal (and thus are) Tube/vase sponges don't need help from moving water to send that ejected water away, which is why they're adapted to slow-moving quiet waters.
causal (because of their shape) The tube/vase shape causes strong currents to dislodge them from the ocean floor.
conditional (cannot live) Strong current → tube/vase sponge can't live
Tube/vase sponges were widespread during the late Jurassic period.
Evaluate
With this many claims, it's impossible to know exactly where the answer might pull support from, but when we see Conditional / Causal / Mathematical / Pivot indicator words, that's usually a clue.
And if we can find any Overlapping Concepts, that's also a clue about which claims will be combined.
There's a pivot (however) in the second to last claim as well as a conditional (cannot). So that claim sticks out as being spicier.
When we see Conditionals on Inference questions, we always have two specific questions on our mind:
1. Are there other conditionals that I could chain this one up with? (not in this case; this was the only conditional)
2. Is there some fact that I can apply this conditional to (usually via contrapositive)?
Yes! The contrapositive of the conditional was this:
if tube/vase sponges → then not strong are living currents
We know that both tube and vase sponges were widespread during the late Jurassic, so we can apply that conditional and derive that "not strong currents" were widespread during the late Jurassic.
The tube/vase sponge overlaps with other claims too. We learn that they are well adapted to slow waters because they don't need help from a fast moving current to eject their post-filtered water. But we also learn that they are poorly adapted to strong currents, because those would dislodge them from the ocean floor.
So we could see an answer synthesizing those two facts about the pace of the surrounding water ... i.e. .
Goal
The most likely suspect would be applying the conditional, via contrapositive, to the final sentence, to derive that .
But stay flexible and look for the most provable answer.