Please explain answer

Consider the CREATE PROCEDURE command shown in the figure (lines 95 through 114). The words IN that you see in line 97 and line 98 are completely optional. That is, if you dropped the procedure and recreated it after deleting the word IN from both line 97 and line 98, the stored procedure would function exactly the same after the change 95 CREATE PROCEDURE update invoices credit total 96 97 invoice_numb er_param IN VARCHAR2 98 credit_total_param IN NUMBER 99 update_count OUT INTEGER 100 101 AS 102 BEGIN 103 UPDATE invoices 104 SET credit total credit_total_param 105 WHERE invoice number invoice number param 106 SELECT COUNT INTO update_count 10 108 WHERE invoice number-invoice number param 109 COMMIT 110 EXCEPTION 111 WHEN OTHERS THEN 112 SELECT 0 INTO update_count FROM dual 113 ROLLBACK 114 END 115 FROM invoices O True False