34. AstraZeneca PLC is a biopharmaceutical company headquartered in London, United Kingdom. In AstraZeneca's December 31, 2014 Form 20-F filed with the United States Securities and Exchange Commission, the Company described the following joint venture arrangement:

On 30 April 2014, AstraZeneca entered into a joint venture agreement with Samsung Biologics Co. Ltd, to develop a biosimilar using the combined capabilities of the two parties. The agreement resulted in the formation of a joint venture entity based in the UK, Archigen Biotech Limited, with a branch in South Korea. AstraZeneca contributed $70m in cash to the joint venture entity and has a 50% interest in the joint venture. The investment is measured using the equity method. A summarized Statement of Financial Position for Archigen Biotech Limited is set out below:

(in millions)	31 December 2014
Noncurrent assets	$76
Current assets	58
Current liabilities	(6)
Net assets	128
Share capital	140
Retained earnings	(12)
Total equity	$128

AstraZeneca reported that its equity investment in Archigen Biotech Limited was equal to $64 million before currency translation adjustments.

a. Confirm that the Equity Investment on AstraZeneca's balance sheet is the correct balance.

b. AstraZeneca's investment balance on December 31, 2014 is less than its initial investment on April 30, 2014. What is the most likely cause of the decrease? How do you know?