His Answer is that she should look for the currant, and her Service is to restock the extinct dragon population of Xanth. To this end she needs to recruit dragons from one of Ida’s moons.
He suggests she find a source of current (likely referring to a water source) and her task is to revive the extinct dragon population on the planet Xanth.  To accomplish this, she must gather dragons from one of Ida's moons.