According to Stockholm International Peace Research Institute data for 2016, which country, with defence spending of 55 point 9 billion US dollars, became the world's fifth largest military spender?

Introduction / Context:
This question checks knowledge of global defence expenditure rankings based on data from the Stockholm International Peace Research Institute, an authority on military spending statistics. Examinations use such questions to test awareness of India's position in the world in terms of defence spending and to encourage understanding of how India compares with major powers like the United States of America, China, Russia, and Saudi Arabia.

Given Data / Assumptions:

• The year of reference is 2016.
• The source is Stockholm International Peace Research Institute, often abbreviated as SIPRI.
• The spending amount mentioned is 55 point 9 billion US dollars.
• The rank in question is fifth largest military spender in the world.
• The options list China, United States of America, Russia, India, and Saudi Arabia.

Concept / Approach:
The ranking of military spending typically has the United States of America at the top, followed by China, and then by other large spenders like Russia and Saudi Arabia. Around 2016, India increased its defence expenditure significantly, reaching an estimated 55 point 9 billion US dollars and thereby becoming the world's fifth largest military spender according to SIPRI. The approach is to remember that this combination of number and ranking refers specifically to India, not to the larger spending powers.

Step-by-Step Solution:
Step 1: Recall that SIPRI publishes an annual report on military expenditure by country. Step 2: Remember that in the 2016 data, the biggest spender was the United States of America, followed by China, and then by other large powers. Step 3: Note that a spending figure around 55 to 56 billion US dollars and the position of fifth largest spender are associated with India in that period. Step 4: Check the options and identify India as the one that matches this combination of rank and expenditure level. Step 5: Select India as the correct answer.

Verification / Alternative check:
Verification can be done by consulting a summary of SIPRI military expenditure data for 2016. These summaries clearly show that India spent approximately 55 point 9 billion US dollars on defence and ranked fifth worldwide. By comparison, the United States of America and China spent much higher amounts and occupied the top two positions, while Russia and Saudi Arabia were also above India in earlier years but around this time India moved into the fifth position. Since only India fits the specific data mentioned in the question, this provides strong confirmation.

Why Other Options Are Wrong:
China: China was ranked second, not fifth, and its defence spending was significantly higher than 55 point 9 billion US dollars, so this option is incorrect.
United States of America: This country has the largest defence budget in the world and spends far more than the amount mentioned, so it cannot be the fifth largest spender here.
Russia: Russia is a major military power, but the figure 55 point 9 billion US dollars and the fifth rank in 2016 do not match it in the SIPRI table.
Saudi Arabia: Saudi Arabia is also a high spender on defence, but the combination of amount and rank in this question does not correspond to it in the 2016 data.

Common Pitfalls:
A common error is to assume that any high figure must refer to China or the United States of America without paying attention to the rank mentioned. Some learners also confuse older rankings where other countries like Saudi Arabia appeared higher, or they mix data from different years. Another trap is to underestimate India's defence budget and rule it out as a top five spender. Careful reading of both the spending level and the rank, and linking them to the correct year, helps avoid these mistakes.

Final Answer:
India, with spending of about 55 point 9 billion US dollars in 2016, became the world's fifth largest military spender according to SIPRI.