$($a$)$ Answer the following question related to functional dependency.

$($i$)$ Define the term functional dependency.

$($ii$)$ Can a software design tool identify functional dependencies? Briefly

explain your answer.

$(2$ marks$)$

$($b$)$ Consider the attribute set $R=$ABCDEF and the functional dependency set

$F=\{ADB,AE,CE,$DEF$A,FD\}.$ Assess a way to find a

candidate key of $R.$

$(4$ marks$)$

$($c$)$ Explain the impact of functional dependencies on database security and the

potential vulnerabilities that can be prevented.

$(4$ marks$)$

$($d$)$ Figure $1$ shows the invoice issued for pets' vaccination at HILLTOP Animal

Hospital. The issued invoice contains the information on customer and pet. Each

customer and pet identified uniquely in every receipt issued.

Figure $1$: Invoice

Create new relations by transforming the unnormalized table in Figure $1$ from

UNF to $3NF.$

$(13$ marks$)$