Its marking of the box "To be refunded" in its 2005 annual ITR constituted its exercise of the option, and from then onwards Rhombus became precluded from carrying-over the excess creditable withholding tax...
The quarterly tax payments are advance payments of the tax due on the entire taxable income of that particular taxable year. Thus, these quarterly tax payments are deducted from the total tax due for the entire year as indicated in the final adjustment return...