How many complaints on credit cards in the year 2016 were filed by male clients?
credit cards refers to Product = 'Credit card'; 2016 refers to year(Date received) = 2016; male refers to sex = 'Male';
SELECT COUNT(T1.sex) FROM client AS T1 INNER JOIN events AS T2 ON T1.client_id = T2.Client_ID WHERE strftime('%Y', T2.`Date received`) = '2016' AND T1.sex = 'Male' AND T2.Product = 'Credit card'