If you have transferred money into or out of your account since the last entry, enter the amount in columnC, using a positive number for money added to the account, or a negative number for money withdrawn.
Technically, columnC should also account for the lag between stocks going ex-dividend and the dividend payment, but this should not significantly effect the calculations unless the dividend in question is a significant part of the change in your portfolio value on any given day.
Kaneria had criticised his central contract demotion from category B to C in his online column, but later blamed a newspaper for publishing his words out of context.