Consider the following example of an SDD: If A $->$ BCD$,$ then C$.$val $=$ A$.$val, C$.$val $=$ B$.$val, C$.$val $=$ D$.$val. What is true about this SDD$?$

a$.$

The attributes involved are synthesized

b$.$

The attributes involved are inherited

c$.$

The SDD is S$-$attributed

d$.$

The SDD cannot be L$-$attributed