(2) Consider the following relation for a relational database: (5 Marks) Appointments (PatientID, PatientName, Date, Time, Primary Doctor) Mohammad has created this table. a) Mohammad grants the Select permission to Ahmad on this table with grant option, then Ahmad grants Select to Sara. Can Ahmad now grant Select to Omar? Can Ahmad grant Insert to Omar? (1 Mark) b) How can Mohammad grant Select on a subset of the columns, say PatientName, Date, Time, to Khalid? (2 Marks, support your answer with SQL) c) How can Mohammad grant Select on a subset of the rows, say those patients whose Primary Doctor is Dr. Issa, to Khalid? (2 Marks, support your answer with SQL)