Supermarket chains Giant and Sheng Siong cater to the mass market in Singapore. On 21 May 2021, Sheng Siong discounted Golden Pineapple rice to S$12.50 for four weeks. Sheng Siong's advertisement did not state the regular price. On 3 June 2021, Giant discounted Golden Eagle rice to S$12.90 for one week, highlighting "Was $15.80." a. Some consumers are busy, while others have time to shop. Some consumers buy only small quantities, while others buy large amounts. Explain the differences in their benefit vis--vis cost of economizing. b. How do random discounts exploit the differences in (a)? c. Explain why Giant highlighted the list price. d. How would the list price of Golden Eagle price affect the demand for Giant's private label rice at S$7.30 after the Golden Eagle promotion ends.