As a part of the space-research program, a physiologist was asked to investigate the effect of flight-induced stress on blood pressure. Accordingly, the blood pressure of the cosmonauts was to be measured twice: once before the take-off and once after the spacecraft entered the designated orbit around the earth. For a proper comparison, the preflight blood pressure should be recorded in
The lying down position The sitting position The standing position Any position, as long as the post-flight recording is made in the same position