In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.

Example input: Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lo during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Link Information: Operation Market Garden was a failed World War II military operation fought in the Netherlands from 17 to 25 September 1944. Answer: from 17 to 25 September 1944
Example output: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin?
Example explanation: The passage describes the 704th's actions during Operation Market Garden, and the answer specifies when the operation happened.
Q: Passage: St Jude's is constructed in yellow sandstone ashlar with a slate roof. Its plan is rectangular and consists of a nave and chancel in one cell with no division between them, a vestry attached to the east end of the chancel, and a bellcote on the gable at the west end. Above the bellcote is a canopy decorated with crockets. The west front contains a double door, above which is a triple lancet window with a circular window over it. At the corners are square turrets which become octagonal as they rise, and each is surmounted by a spire. On each side of the church are five pairs of lancet windows, each pair being separated by a buttress. Above the vestry at the east end is another triple lancet window, over which is a cricketed gable.
Link Information: Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism Answer: low-grade regional metamorphism
A:
What type of geological process forms the rock that is the roof of the church?