( 11 ) The value of a stock portfolio investment, in dollars, t months after January 19, 2019 is given by V(t). On July 18, 2019 (t = 6), the value of the portfolio was $18,000. The first derivative, V' (t), decreased since the start of the investment reaching a low of $2,000 per month on July 1st, 2019, then increased for the rest of the year. Which of the following must be correct? (A) The investment increased in value throughout 2019. (B) The investment decreased in value for the first 6 mos. of 2019 and increased for the last 6 mos. (C) The value of the was lower on July 18, 2019 than at any other time. (D) On August 18, 2019, the value of the investment was $16,000. (E) On August 1st, 2019, the value of the investment was $20,000