The correct answers are foreign tourism and war reparations.
Foreign Tourism
During the 1920's tourism was an important economic sector in France, but due to the Wall Street crack in 1929, many big economies entered in a period of recession which caused the downfall of foreign tourist flow. This hit the French economy which entered in recession in 1931.
War reparations
In 1923 Germany's economy was in default and, for that reason, it couldn't afford any longer the war reparations payments it engaged to pay to France in the Treaty of Versailles. These war reparations payments were an important source of economic resources for France, used mainly to pay war loans that France had with the US. Without this source of money, the French economy started to cripple.
