If you are doing this assignment in Ms. Word, for your convenience, the followings are the symbols for the Relational Algebra operations that you might use: Relation Model \# Question 1a. Please select three main parts that a data model describes (10 pt.) a. The order of the rows of the data to be stored b. The structure of the data to be stored c. The operations on the data to be stored d. The order of the columns of the data to be stored e. The constraints on the data to be stored \#Question -1b. Please select valid relations (10 pt.) a. Relation1