The phrase "a core question is" is correct and usable in written English.
It can be used when introducing an important or fundamental question related to a topic being discussed.
Example: "In the context of climate change, a core question is how we can effectively reduce carbon emissions."
Alternatives: "a fundamental question is" or "a key question is".
In the midst of these developments, a core question is being asked: what role should the agency, with its credo of dispassionate reporting, play now, when the Bush administration is passionate about fighting terrorism with every available weapon?
"A core question is whether, in examining this nation's history and tradition, the Court will protect only those interests supported by a specific and longlasting tradition, or whether the Court will not so constrict its analysis," Senator Joseph Biden said during hearings on David Souter's nomination, in 1990.
For me, a core question is: how will I make use of and invest my privilege as a white male of European descent (although an immigrant), whose job is to teach and do research in food studies?
Thus a core question is to determine whether the process provides value for money and a sustainable return.
A core question is: "What is the smallest change in score in the construct to be measured which patients consider important?
The core question is this: Is S-9 a polluter, subject to regulation by the Environmental Protection Agency and state agencies that protect the nation's water supply?
When analyzing the possibility of a carbon tax, the core question is whether a carbon tax is likely to be less costly and more efficient than existing command and control policies.
Now we are entering a different conflict, one whose core question is "Who owns 3D printing?" The origin of this quandary lies with the creation of the RepRap Project, an open source effort to create a machine that can build itself.
The core question is a better understanding of the factors that contribute to maintaining the active participation of the gambler and his/her pervasive practice.
The core question is: 'What would interest a reporter and interest a reader?' If it's not a good story, why pitch it?" Mr. Bender added: "We literally sit down and pretend we're journalists again".
The core question is whether any military options can provide an enduring solution.
