Altitude above sea level is given in positive value and below sea level is given in negative values. what situation describes a hiker in death valley stopping at altitude of 0 feet. a) the hiker starts at 10 feet then increases altitude by 10 feet. b) the hiker starts at -10 feet the decreases altitude by 10 feet. c) the hiker starts at -10 feet then increases altitude by 10 feet. d) the hiker starts at 0 feet and then decreases altitude by 10 feet