Detailed Instructions: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Q: In the UK, the Medicines and Healthcare Products Regulatory Agency approves drugs for use, though the evaluation is done by the European Medicines Agency, an agency of the European Union based in London. Normally an approval in the UK and other European countries comes later than one in the USA. Then it is the National Institute for Health and Care Excellence (NICE), for England and Wales, who decides if and how the National Health Service (NHS) will allow (in the sense of paying for) their use. The British National Formulary is the core guide for pharmacists and clinicians.
A:
Who is the core guide?