I have a question in sql queries

I have the following script for the tables of the database:

create table bank(BNUM int primary key, BNAME VARCHAR(20) NOT NULL, EstDate date); create table branch(BranchName varchar(20) primary key, BNUM int not null, foreign key(bnum) references bank(BNUM) ); create table customer (CNUM int primary key, addr varchar(20), dob date); create table serve (CNUM int, BNUM int, primary key (CNUM, BNUM),foreign key(CNUM) references customer(CNUM), foreign key (BNUM) references bank(BNUM)); create table loan (LNUM int primary key, interestRate double not null, amount double not null, CNUM int , foreign key (CNUM) references customer(CNUM)); create table savingAcc (ANUM int primary key, balance double, overdraftAmount double, CNUM int, foreign key (CNUM) references customer(CNUM)); create table checkingAcc (ANUM int primary key, balance double, interestRate double, CNUM int, foreign key (CNUM) references customer(CNUM)); create table payment (PNUM int primary key, amount double, Pdate date, LNUM int, foreign key (LNUM) references loan(LNUM)); 

a) Who is the owner of the account with highest balance?