Fort Worth-based D.R. Horton Inc reported a 173 percent jump in quarterly profit for its second fiscal quarter ended March 31, reflecting the increasing strength of the housing market. Net income increased to $111 million, or 32 cents per share, in the second quarter from $40.6 million, or 13 cents per share, a year earlier. Revenue rose 49 percent ot $1.39 billion. Homes closed in the quarter increased 33 percent to 5,643, compared to 4,240 homes in the year-ago quarter. “The spring selling season is off to a strong start at D.R. Horton, with robust demand driving higher sales volumes and favorable pricing, which is reflected in the 14 percent increase in our average selling price,” said Donald R. Horton, chairman, in a statement. “ We are in an excellent position to continue to meet increased sales demand and aggregate market share with 15,800 homes in inventory and 175,000 lots owned or controlled under option contracts, of which 58,000 lots are fully developed. “