9). Sonja is a US citizen who has worked in Spain for the past 10 months. She received $8,000 a month as compensation. Her employer has offered to extend Sonja's contract to work in Spain for another 6 months at the same rate of pay. If she rejects the offer, she can return to the US and receive a salary of $10,000 per month. While working in Spain, she is subject to the Spanish income tax, which is approximately 11% of her gross pay. The marginal tax rate on her income taxed in the US is 24%. Should Sonja stay in Spain or return to the US? (Assume all income in this problem are taxed at the marginal tax rates indicated.)