What caused conflict leading up to the First Crusade? Seljuks took control of Jerusalem and attacked the Byzantine Empire.
Seljuks attacked churches and forced Christians to leave the Holy Land.
Seljuks broke a peace deal with the church and closed Jerusalem to Christians.
Seljuks took control of Antioch and removed church officials who came to make peace.

Correct answer is Seljuks took control of Jerusalem and attacked the Byzantine Empire.

Explanation:

First option is correct as after the battle of Manzikert in 1071 the Seljuks defeated Byzantine army and killed their emperor. Just a couple of years later, they conquered Jerusalem and continued pressing the Empire. That is why the Byzantine Emperor called the Pope and western leaders to help them.

All other options are not correct as they historically never happened, or to be precise they didn't led to First Crusade.

union blockade

explanation:

the union blockade in the american civil war was a naval strategy by the united states to prevent the confederacy from trading.

the blockade was proclaimed by president abraham lincoln in april 1861, and required the monitoring of 3,500 miles (5,600 km) of atlantic and gulf coastline, including 12 major ports, notably new orleans and mobile. those blockade runners fast enough to evade the union navy could only carry a small fraction of the supplies needed. they were operated largely by british citizens, making use of neutral ports such as havana, nassau and bermuda. the union commissioned around 500 ships, which destroyed or captured about 1,500 blockade runners over the course of the war.