Which of the following is a correctly formatted SELECT statement to show the result set with the customer's first name, last name, and the invoice total?

a$.)$

SELECT first$\_$name, last$\_$name,

total

FROM customer

JOIN invoice

ON customer$\_$id$=$customer$\_$id;

b$.)$

SELECT first$\_$name, last$\_$name,

total

FROM customer

JOIN invoice

ON customer.customer$\_$id$=$invoice.customer$\_$id

c$.)$

SELECT first$\_$name, last$\_$name,

total

FROM customer

JOIN invoice

ON customer.cust$\_$id$=$invoice.customer$\_$id

d$.)$

SELECT first$\_$name, last$\_$name,

total

FROM customer

JOIN invoice

ON customer$\_$id;