Concept:A cell reference in a spreadsheet is made up of a column letter and a row number.Explanation:In spreadsheet programs, columns are labelled with letters such as A, B, C, and rows are labelled with numbers such as 1, 2, 3.A single box where data is entered is called a cell, and it is identified by combining its column letter and row number, for example, A1 or B2.Therefore, the term identified by a letter and a number is a cell.Answer:B. Cell