This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Passage: Desktop computers and laptops are commonly infected with malware either to gather passwords or financial account information, or to construct a botnet to attack another target. Smart phones, tablet computers, smart watches, and other mobile devices such as Quantified Self devices like activity trackers have also become targets and many of these have sensors such as cameras, microphones, GPS receivers, compasses, and accelerometers which could be exploited, and may collect personal information, including sensitive health information. Wifi, Bluetooth, and cell phone network on any of these devices could be used as attack vectors, and sensors might be remotely activated after a successful breach. Question: Activity trackers are an example of what?
Quantified Self devices

Passage: When World War II started, tonnage levels at the port decreased and shipping activities were suspended; however, the war did provide economic benefits for the city. Petrochemical refineries and manufacturing plants were constructed along the ship channel because of the demand for petroleum and synthetic rubber products by the defense industry during the war. Ellington Field, initially built during World War I, was revitalized as an advanced training center for bombardiers and navigators. The Brown Shipbuilding Company was founded in 1942 to build ships for the U.S. Navy during World War II. Due to the boom in defense jobs, thousands of new workers migrated to the city, both blacks and whites competing for the higher-paying jobs. President Roosevelt had established a policy of non-discrimination for defense contractors, and blacks gained some opportunities, especially in shipbuilding, although not without resistance from whites and increasing social tensions that erupted into occasional violence. Economic gains of blacks who entered defense industries continued in the postwar years. Question: Why did thousands of new workers flock to Houston?
defense jobs

Passage: The large external sculptural schemes of Early Gothic churches gave way to more sculpture inside the building, as tombs became more elaborate and other features such as pulpits were sometimes lavishly carved, as in the Pulpit by Giovanni Pisano in Sant'Andrea. Painted or carved wooden relief altarpieces became common, especially as churches created many side-chapels. Early Netherlandish painting by artists such as Jan van Eyck (d. 1441) and Rogier van der Weyden (d. 1464) rivalled that of Italy, as did northern illuminated manuscripts, which in the 15th century began to be collected on a large scale by secular elites, who also commissioned secular books, especially histories. From about 1450 printed books rapidly became popular, though still expensive. There were around 30,000 different editions of incunabula, or works printed before 1500, by which time illuminated manuscripts were commissioned only by royalty and a few others. Very small woodcuts, nearly all religious, were affordable even by peasants in parts of Northern Europe from the middle of the 15th century. More expensive engravings supplied a wealthier market with a variety of images. Question: Who carved the Pulpit in Sant'Andrea?

Giovanni Pisano