During the year, a private college received the following pledges: (a) $2,500,000 from an alumnus to construct a new wing for a science building; (b) $4,500,000 to be used for general education purposes; (c) $5,000,000 to be used to acquire securities, only the earnings of which may be used to support teaching, research and other routine activities of the university; and (d) up to $1,000,000 to be used to match other expected contributions to a scholarship fund in honor of a recently retired faculty member. How should these pledges be accounted for?