Christina, single, Filipino with 1 dependent child, received in the taxable year 2020 the following professional fees as an independent consultant: Monthly Fees Less 5% CWT Net Monthly Fees P240,000 P12,000 P228,000 The monthly cost of her professional services amounted to P20,000, gross of the CWT. The office rental expenses related to her consultancy business amounted to Monthly rental expense Less 5% CWT Monthly rental expense paid P30,000 P1,500 P28,500 She is not VAT-registered and instead pays 3% OPT on her gross receipts under Section 116 of the Tax Code Aside from her consultancy business, she is a faculty member of CPAR University from which she received the following employment income for the same year: Gross pay Less CWT Fewer SSS premiums Net Pay and union dues P850,000 P60,000 P6,000 P784,000 The amount she received from CPAR University is inclusive of 13th Month Pay and other benefits of P165,000. Her car fuel expenses amounted to P10,000 per month. 

She used the car for her consultancy business 40% of the time. She also wrote a book entitled "SINGLE LIFE IS HEAVEN" which became a bestseller in the Philippines. In 2020, she earned royalties from the book in the amount of P2,500,000, net of the 10% final tax. Using this amount, she opened a time deposit with BDO which earned an interest income of P75,000, net of the 20% final tax. She has excess tax credits from the prior year of P15,500.

Required: Calculate her tax payable in the 1st, 2nd, 3rd quarters if she chooses OSD (Optional Standard Deduction)? Calculate her tax payable in the annual ITR if she chooses OSD (Optional Standard Deduction)?