The taxpayer who is a resident of Thailand may elect to pay tax at the rate of 10.0 per cent of the income, instead of calculating the amount of tax as under (1) and (2), only for the income under Section 40 (4) (b) received from a company or juristic partnership established under the Thai law, a mutual fund, or a financial institution established under a specific law in Thailand for the purpose of providing a loan in order to promote agriculture, commerce or industry.