Study the following information carefully to answer the question below.
Eight persons A, B, C, D, E, F, G and H work for three different companies namely X, Y and Z. Not more than three persons work for a company. There are only two ladies in the group who have different specializations and work for different companies. Of the group of friends, two have specialization in each HR, Finance and Marketing. One member is an engineer and one is a doctor. H is an HR specialist and works with a Marketing specialist B who does not work for company Y. C is an engineer and his sister works in company Z. D is a specialist in HR working in company X while her friend G is a finance specialist and works for company Z. No two persons having the same specialization work together. Marketing specialist F works for company Y and his friend A who is a Finance expert works for company X in which only two specialists work. No lady is a marketing specialist or a doctor.
For which of the following companies does C work ?