Answer:
IBM could either diversify by the strategy of market penetration, which consists in increasing the market share in a particular sector (in this case, cloud computing) through more marketing efforts.
Or it could integrate horizontally, acquiring a possible competitor that is more advanced in the cloud-computing business. Or even a start-up with good prospects, because with the amount of capital that IBM has, it could more easily expand the start-up operation as a new internal business division.